WOMEN haemorrhaging blood after a sexual attack are no longer considered an emergency by the NSW Ambulance Service.

The reduced urgency rating has been also extended to women suffering a second-trimester miscarriage or suddenly giving birth outside of a hospital.

All three scenarios were previously considered Category 1 priority responses.

The shift to a less serious category means responding ambulances will only be assigned when available, and will not need to drive with emergency lights or sirens.

Some gunshot victims, those seriously injured in suicide attempts and people haemorrhaging from other serious assaults have also been downgraded to Category 2.

A statement from shadow minister for the prevention of domestic violence and sexual assault Jodie Harrison said even multiple victims of a nuclear, chemical or biological disaster would now be classified as "potentially serious" under the new benchmarks.

"People who are calling for ambulances are clearly in need of help. Making them wait longer puts patient safety at risk," she said.

"It is mortifying to think that victims who have already suffered severe trauma would be told their cases aren't a priority and then be made to wait even longer."

Health Minister Jillian Skinner blamed the downgrading on changes to international triage codes.

She told parliament NSW should come up with its own set of codes if the global medical community failed to return the injury types to their former first-tier seriousness rating.

"I do not believe that people suffering those conditions should wait," she said.

"I have asked for those international triage codes to be looked at.

"If necessary, NSW will take the lead in coming up with a different set of codes.

"I will take that, then, to the ministers' council and overseas, if necessary."